utdelete.c

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/*******************************************************************************
 *
 * Module Name: utdelete - object deletion and reference count utilities
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "acevents.h"

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utdelete")

/* Local prototypes */
static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);

static void
acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_internal_obj
 *
 * PARAMETERS:  object         - Object to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Low level object deletion, after reference counts have been
 *              updated (All reference counts, including sub-objects!)
 *
 ******************************************************************************/

static void acpi_ut_delete_internal_obj(union acpi_operand_object *object)
{
    void *obj_pointer = NULL;
    union acpi_operand_object *handler_desc;
    union acpi_operand_object *second_desc;
    union acpi_operand_object *next_desc;
    union acpi_operand_object **last_obj_ptr;

    ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);

    if (!object) {
        return_VOID;
    }

    /*
     * Must delete or free any pointers within the object that are not
     * actual ACPI objects (for example, a raw buffer pointer).
     */
    switch (object->common.type) {
    case ACPI_TYPE_STRING:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "**** String %p, ptr %p\n", object,
                  object->string.pointer));

        /* Free the actual string buffer */

        if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {

            /* But only if it is NOT a pointer into an ACPI table */

            obj_pointer = object->string.pointer;
        }
        break;

    case ACPI_TYPE_BUFFER:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "**** Buffer %p, ptr %p\n", object,
                  object->buffer.pointer));

        /* Free the actual buffer */

        if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {

            /* But only if it is NOT a pointer into an ACPI table */

            obj_pointer = object->buffer.pointer;
        }
        break;

    case ACPI_TYPE_PACKAGE:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  " **** Package of count %X\n",
                  object->package.count));

        /*
         * Elements of the package are not handled here, they are deleted
         * separately
         */

        /* Free the (variable length) element pointer array */

        obj_pointer = object->package.elements;
        break;

        /*
         * These objects have a possible list of notify handlers.
         * Device object also may have a GPE block.
         */
    case ACPI_TYPE_DEVICE:

        if (object->device.gpe_block) {
            (void)acpi_ev_delete_gpe_block(object->device.
                               gpe_block);
        }

        /*lint -fallthrough */

    case ACPI_TYPE_PROCESSOR:
    case ACPI_TYPE_THERMAL:

        /* Walk the address handler list for this object */

        handler_desc = object->common_notify.handler;
        while (handler_desc) {
            next_desc = handler_desc->address_space.next;
            acpi_ut_remove_reference(handler_desc);
            handler_desc = next_desc;
        }
        break;

    case ACPI_TYPE_MUTEX:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "***** Mutex %p, OS Mutex %p\n",
                  object, object->mutex.os_mutex));

        if (object == acpi_gbl_global_lock_mutex) {

            /* Global Lock has extra semaphore */

            (void)
                acpi_os_delete_semaphore
                (acpi_gbl_global_lock_semaphore);
            acpi_gbl_global_lock_semaphore = NULL;

            acpi_os_delete_mutex(object->mutex.os_mutex);
            acpi_gbl_global_lock_mutex = NULL;
        } else {
            acpi_ex_unlink_mutex(object);
            acpi_os_delete_mutex(object->mutex.os_mutex);
        }
        break;

    case ACPI_TYPE_EVENT:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "***** Event %p, OS Semaphore %p\n",
                  object, object->event.os_semaphore));

        (void)acpi_os_delete_semaphore(object->event.os_semaphore);
        object->event.os_semaphore = NULL;
        break;

    case ACPI_TYPE_METHOD:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "***** Method %p\n", object));

        /* Delete the method mutex if it exists */

        if (object->method.mutex) {
            acpi_os_delete_mutex(object->method.mutex->mutex.
                         os_mutex);
            acpi_ut_delete_object_desc(object->method.mutex);
            object->method.mutex = NULL;
        }
        break;

    case ACPI_TYPE_REGION:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "***** Region %p\n", object));

        /*
         * Update address_range list. However, only permanent regions
         * are installed in this list. (Not created within a method)
         */
        if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
            acpi_ut_remove_address_range(object->region.space_id,
                             object->region.node);
        }

        second_desc = acpi_ns_get_secondary_object(object);
        if (second_desc) {
            /*
             * Free the region_context if and only if the handler is one of the
             * default handlers -- and therefore, we created the context object
             * locally, it was not created by an external caller.
             */
            handler_desc = object->region.handler;
            if (handler_desc) {
                next_desc =
                    handler_desc->address_space.region_list;
                last_obj_ptr =
                    &handler_desc->address_space.region_list;

                /* Remove the region object from the handler's list */

                while (next_desc) {
                    if (next_desc == object) {
                        *last_obj_ptr =
                            next_desc->region.next;
                        break;
                    }

                    /* Walk the linked list of handler */

                    last_obj_ptr = &next_desc->region.next;
                    next_desc = next_desc->region.next;
                }

                if (handler_desc->address_space.handler_flags &
                    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {

                    /* Deactivate region and free region context */

                    if (handler_desc->address_space.setup) {
                        (void)handler_desc->
                            address_space.setup(object,
                                    ACPI_REGION_DEACTIVATE,
                                    handler_desc->
                                    address_space.
                                    context,
                                    &second_desc->
                                    extra.
                                    region_context);
                    }
                }

                acpi_ut_remove_reference(handler_desc);
            }

            /* Now we can free the Extra object */

            acpi_ut_delete_object_desc(second_desc);
        }
        break;

    case ACPI_TYPE_BUFFER_FIELD:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "***** Buffer Field %p\n", object));

        second_desc = acpi_ns_get_secondary_object(object);
        if (second_desc) {
            acpi_ut_delete_object_desc(second_desc);
        }
        break;

    case ACPI_TYPE_LOCAL_BANK_FIELD:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "***** Bank Field %p\n", object));

        second_desc = acpi_ns_get_secondary_object(object);
        if (second_desc) {
            acpi_ut_delete_object_desc(second_desc);
        }
        break;

    default:
        break;
    }

    /* Free any allocated memory (pointer within the object) found above */

    if (obj_pointer) {
        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "Deleting Object Subptr %p\n", obj_pointer));
        ACPI_FREE(obj_pointer);
    }

    /* Now the object can be safely deleted */

    ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
              object, acpi_ut_get_object_type_name(object)));

    acpi_ut_delete_object_desc(object);
    return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_internal_object_list
 *
 * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: This function deletes an internal object list, including both
 *              simple objects and package objects
 *
 ******************************************************************************/

void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
{
    union acpi_operand_object **internal_obj;

    ACPI_FUNCTION_TRACE(ut_delete_internal_object_list);

    /* Walk the null-terminated internal list */

    for (internal_obj = obj_list; *internal_obj; internal_obj++) {
        acpi_ut_remove_reference(*internal_obj);
    }

    /* Free the combined parameter pointer list and object array */

    ACPI_FREE(obj_list);
    return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_ref_count
 *
 * PARAMETERS:  object          - Object whose ref count is to be updated
 *              action          - What to do
 *
 * RETURN:      New ref count
 *
 * DESCRIPTION: Modify the ref count and return it.
 *
 ******************************************************************************/

static void
acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
{
    u16 count;
    u16 new_count;

    ACPI_FUNCTION_NAME(ut_update_ref_count);

    if (!object) {
        return;
    }

    count = object->common.reference_count;
    new_count = count;

    /*
     * Perform the reference count action (increment, decrement, force delete)
     */
    switch (action) {
    case REF_INCREMENT:

        new_count++;
        object->common.reference_count = new_count;

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "Obj %p Refs=%X, [Incremented]\n",
                  object, new_count));
        break;

    case REF_DECREMENT:

        if (count < 1) {
            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                      "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
                      object, new_count));

            new_count = 0;
        } else {
            new_count--;

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                      "Obj %p Refs=%X, [Decremented]\n",
                      object, new_count));
        }

        if (object->common.type == ACPI_TYPE_METHOD) {
            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                      "Method Obj %p Refs=%X, [Decremented]\n",
                      object, new_count));
        }

        object->common.reference_count = new_count;
        if (new_count == 0) {
            acpi_ut_delete_internal_obj(object);
        }
        break;

    case REF_FORCE_DELETE:

        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                  "Obj %p Refs=%X, Force delete! (Set to 0)\n",
                  object, count));

        new_count = 0;
        object->common.reference_count = new_count;
        acpi_ut_delete_internal_obj(object);
        break;

    default:

        ACPI_ERROR((AE_INFO, "Unknown action (0x%X)", action));
        break;
    }

    /*
     * Sanity check the reference count, for debug purposes only.
     * (A deleted object will have a huge reference count)
     */
    if (count > ACPI_MAX_REFERENCE_COUNT) {
        ACPI_WARNING((AE_INFO,
                  "Large Reference Count (0x%X) in object %p",
                  count, object));
    }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_object_reference
 *
 * PARAMETERS:  object              - Increment ref count for this object
 *                                    and all sub-objects
 *              action              - Either REF_INCREMENT or REF_DECREMENT or
 *                                    REF_FORCE_DELETE
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Increment the object reference count
 *
 * Object references are incremented when:
 * 1) An object is attached to a Node (namespace object)
 * 2) An object is copied (all subobjects must be incremented)
 *
 * Object references are decremented when:
 * 1) An object is detached from an Node
 *
 ******************************************************************************/

acpi_status
acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
{
    acpi_status status = AE_OK;
    union acpi_generic_state *state_list = NULL;
    union acpi_operand_object *next_object = NULL;
    union acpi_operand_object *prev_object;
    union acpi_generic_state *state;
    u32 i;

    ACPI_FUNCTION_TRACE_PTR(ut_update_object_reference, object);

    while (object) {

        /* Make sure that this isn't a namespace handle */

        if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                      "Object %p is NS handle\n", object));
            return_ACPI_STATUS(AE_OK);
        }

        /*
         * All sub-objects must have their reference count incremented also.
         * Different object types have different subobjects.
         */
        switch (object->common.type) {
        case ACPI_TYPE_DEVICE:
        case ACPI_TYPE_PROCESSOR:
        case ACPI_TYPE_POWER:
        case ACPI_TYPE_THERMAL:

            /*
             * Update the notify objects for these types (if present)
             * Two lists, system and device notify handlers.
             */
            for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
                prev_object =
                    object->common_notify.notify_list[i];
                while (prev_object) {
                    next_object =
                        prev_object->notify.next[i];
                    acpi_ut_update_ref_count(prev_object,
                                 action);
                    prev_object = next_object;
                }
            }
            break;

        case ACPI_TYPE_PACKAGE:
            /*
             * We must update all the sub-objects of the package,
             * each of whom may have their own sub-objects.
             */
            for (i = 0; i < object->package.count; i++) {
                /*
                 * Push each element onto the stack for later processing.
                 * Note: There can be null elements within the package,
                 * these are simply ignored
                 */
                status =
                    acpi_ut_create_update_state_and_push
                    (object->package.elements[i], action,
                     &state_list);
                if (ACPI_FAILURE(status)) {
                    goto error_exit;
                }
            }
            break;

        case ACPI_TYPE_BUFFER_FIELD:

            next_object = object->buffer_field.buffer_obj;
            break;

        case ACPI_TYPE_LOCAL_REGION_FIELD:

            next_object = object->field.region_obj;
            break;

        case ACPI_TYPE_LOCAL_BANK_FIELD:

            next_object = object->bank_field.bank_obj;
            status =
                acpi_ut_create_update_state_and_push(object->
                                 bank_field.
                                 region_obj,
                                 action,
                                 &state_list);
            if (ACPI_FAILURE(status)) {
                goto error_exit;
            }
            break;

        case ACPI_TYPE_LOCAL_INDEX_FIELD:

            next_object = object->index_field.index_obj;
            status =
                acpi_ut_create_update_state_and_push(object->
                                 index_field.
                                 data_obj,
                                 action,
                                 &state_list);
            if (ACPI_FAILURE(status)) {
                goto error_exit;
            }
            break;

        case ACPI_TYPE_LOCAL_REFERENCE:
            /*
             * The target of an Index (a package, string, or buffer) or a named
             * reference must track changes to the ref count of the index or
             * target object.
             */
            if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
                (object->reference.class == ACPI_REFCLASS_NAME)) {
                next_object = object->reference.object;
            }
            break;

        case ACPI_TYPE_REGION:
        default:
            break;  /* No subobjects for all other types */
        }

        /*
         * Now we can update the count in the main object. This can only
         * happen after we update the sub-objects in case this causes the
         * main object to be deleted.
         */
        acpi_ut_update_ref_count(object, action);
        object = NULL;

        /* Move on to the next object to be updated */

        if (next_object) {
            object = next_object;
            next_object = NULL;
        } else if (state_list) {
            state = acpi_ut_pop_generic_state(&state_list);
            object = state->update.object;
            acpi_ut_delete_generic_state(state);
        }
    }

    return_ACPI_STATUS(AE_OK);

      error_exit:

    ACPI_EXCEPTION((AE_INFO, status,
            "Could not update object reference count"));

    /* Free any stacked Update State objects */

    while (state_list) {
        state = acpi_ut_pop_generic_state(&state_list);
        acpi_ut_delete_generic_state(state);
    }

    return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_add_reference
 *
 * PARAMETERS:  object          - Object whose reference count is to be
 *                                incremented
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add one reference to an ACPI object
 *
 ******************************************************************************/

void acpi_ut_add_reference(union acpi_operand_object *object)
{

    ACPI_FUNCTION_TRACE_PTR(ut_add_reference, object);

    /* Ensure that we have a valid object */

    if (!acpi_ut_valid_internal_object(object)) {
        return_VOID;
    }

    ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
              "Obj %p Current Refs=%X [To Be Incremented]\n",
              object, object->common.reference_count));

    /* Increment the reference count */

    (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
    return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_remove_reference
 *
 * PARAMETERS:  object         - Object whose ref count will be decremented
 *
 * RETURN:      None
 *
 * DESCRIPTION: Decrement the reference count of an ACPI internal object
 *
 ******************************************************************************/

void acpi_ut_remove_reference(union acpi_operand_object *object)
{

    ACPI_FUNCTION_TRACE_PTR(ut_remove_reference, object);

    /*
     * Allow a NULL pointer to be passed in, just ignore it. This saves
     * each caller from having to check. Also, ignore NS nodes.
     *
     */
    if (!object ||
        (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
        return_VOID;
    }

    /* Ensure that we have a valid object */

    if (!acpi_ut_valid_internal_object(object)) {
        return_VOID;
    }

    ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
              "Obj %p Current Refs=%X [To Be Decremented]\n",
              object, object->common.reference_count));

    /*
     * Decrement the reference count, and only actually delete the object
     * if the reference count becomes 0. (Must also decrement the ref count
     * of all subobjects!)
     */
    (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
    return_VOID;
}